I recently had a situation where a site within a WordPress multisite was domain mapped and the DNS at the registrar was changed away from the multisite without the multisite install being updated first. This meant that the WordPress site was not available and the client wanted certain information from the original WordPress dashboard.
The solution is luckily very simple.
- Log in to the database powering the WordPress Multisite install (phpMyAdmin or similar)
- Locate the table named “[YOUR PREFIX HERE]domain_mapping”.
- Find the erroneous domain
- Delete the row!
- Sit back and stop worrying.